1. Field of the Disclosure
This disclosure relates generally to drill bits including sensors for providing measurements for a property of interest of a formation and systems using such drill bits.
2. Brief Description of the Related Art
Oil wells (wellbores or boreholes) are drilled with a drill string that includes a tubular member having a drilling assembly (also referred to as the bottomhole assembly or “BHA”) that has a drill bit attached to the bottom end of the BHA. The drill bit is rotated to disintegrate the earth formations to drill the wellbore. The BHA typically includes devices for providing information about parameters relating to the behavior of the BHA, parameters of the formation surrounding the wellbore and parameters relating to the drilling operations. One such parameter is the rate of penetration (ROP) of the drill bit into the formation.
A high ROP is desirable because it reduces the overall time required for drilling a wellbore. ROP depends on several factors including the design of the drill bit, rotational speed (or rotations per minute or RPM) of the drill bit, weight-on-bit type of the drilling fluid being circulated through the wellbore and the rock formation. A low ROP typically extends the life of the drill bit and the BHA. The drilling operators attempt to control the ROP and other drilling and drill string parameters to obtain a combination of parameters that will provide the most effective drilling environment. ROP is typically determined based on devices disposed in the BHA and at the surface. Such determinations often differ from the actual ROP. Therefore, it is desirable to provide an improved apparatus for determining or estimating the ROP.